1. Field of the Invention
The present invention relates to differential transmission mechanisms, particularly a differential utilized in an automotive axle drive.
2. Description of the Prior Art
A differential gear in a final drive axle of a motor vehicle transmits a rotational input from an engine to two axle shafts. A differential case is rotatably supported on an axle housing. Typically, a differential case comprises two halves: a plain differential case half and a flanged differential case half, usually bolted to each other. The flanged differential case half is provided with a flange that receives a ring gear attached to the flange by a number of bolts. In order to provide the adequate stiffness of the differential gear, the flanged differential case half is conventionally provided with a plurality of stiffening ribs.
The ring gear is engaged with a pinion gear of a final drive. In such a case, to account for assembly tolerances, shim packs may be disposed between the ring gear and the flange of the differential case to properly align the ring gear with the pinion gear. Such prior art assemblies are costly and cumbersome.
Furthermore, presently, each model of automobile (both cars and trucks) may have variants having different final drive gear ratios for various specific applications. The different final drive gear ratios require different gear teeth combinations, thus automobile manufacturers need to provide differentials with different gear spacings (or offsets). For instance, heavy duty truck drive axle differential manufacturers have to use up to four different flanged differential case halves to cover the offsets of all gear ratios employed.